Carrabassett Valley, Maine (CNN) -- Several ski-lift riders fell to the ground and others were trapped in the air Tuesday when a lift a broke down at Sugarloaf Ski Resort in Maine.
Before the accident, high winds had delayed the opening of the lift. Conditions at the time of the accident were windy, but not unusually so following a major snowstorm, a spokesman for the resort said.
More than 200 people were trapped up to 90 minutes and as many as nine were injured, officials said.
Ethan Austin, a spokesman for the resort, said the derailment on one tower of the Spillway East lift happened around 10:30 a.m. ET, when lift's cable skipped over the edge of a pulley. Five of the lift's chairs fell 25 to 30 feet and hit the ground, he said.
"The chairs were pretty mangled, but the ski patrol was there right away," patron Ben Martin told CNN affiliate WCSH.
Winds had diminished by midmorning and resort personnel checked the lift prior to opening, Sugarloaf said in a statement. Austin said conditions were basically what is expected after a major storm.
The rescue operation was completed around noon.
The lift will remain closed until the preliminary investigation is completed and it is cleared by the state to resume operation, the resort said.
Franklin Memorial Hospital in Farmington, Maine, was treating eight patients, according to spokeswoman Jill Gray. She could not provide the nature of the injuries or the conditions of the patients. A ninth person originally was taken by ambulance to Franklin Memorial, but that person had to be taken by helicopter to Maine Medical Center in Portland, Gray said.
Sugarloaf said seven people were injured.
Robb Atkinson, a CNN employee who initially was trapped on the lift, said he saw skiers fall from the lift when it came to an abrupt stop during high winds.
"I felt a jerk," said Atkinson, who was riding the lift with his wife. He also described hearing "screams from skiers below" as he watched at least three chairs drop 20 to 30 feet to the ground.
Matt Rolfson, 17, of Albion, Maine, was on a parallel lift with a friend and shot video from his helmet cam of injured skiers.
"People on the lift yelled to see if everyone was OK," said Rolfson, adding a portion of the Spillway East line did a "yo-yo."
He told CNN his lift was unaffected and he skied down later to offer assistance.
High winds were gusting between 30 mph and 50 mph in the area at the time, according to CNN meteorologist Jacqui Jeras, and temperatures at the resort were well below freezing.
Austin said Tuesday afternoon there were an estimated 220 people on the more than 100 chairs on the lift, and the process of evacuating everyone from the chairs dangling above the resort was under way.
"You had to slide off the chair lift 40 feet off the ground into a swing," Atkinson said. After that, skiers were lowered down to the ground and had to ski to the base of the mountain, he said.
Franklin County Emergency officials contacted Gov. John Baldacci with updates on the incident and subsequent rescues, according to David Farmer, Baldacci's deputy chief of staff.
"It's extremely unusual," Austin said. Sugarloaf has never had a lift derailment of this nature in its 60-year history, he added.
The cause of the accident was under investigation.
"We're deeply concerned about those who were injured," said Austin, "and we're committed to understanding the cause of this incident. We want our guests to have fun, but our first priority is their safety."
Two inspectors with the Maine Safety Board were sent to Sugarloaf to investigate, said Farmer. The probe is "protocol for any accident where the state government oversees certification of a ski resort," he added.
The resort is located about 100 miles north of Portland, Maine.
Atkinson and Rolfson said patrons were excited about up to two feet of new snow on the slopes. Both will be back at Sugarloaf on Wednesday.
CNN's Alta Spells, Justin Lear and Phil Gast contributed to this report.